It’s pretty darn dark under the sea, especially in winter. Diver/gardeners tend to the plants. They swim up from below, only their torsos entering the pods, legs dangling in the water.

Under-sea mountains are key locations for predators ... of minerals that support bountiful phytoplankton (tiny drifting plants that are the first link in ocean food chains).

Also, he notes, the relatively steady temperature of the sea water is an ideal environment for plant life. Nemo’s Garden uses hydroponics – a technique that uses water-based nutrients instead ...